“Smart cards” (that is, a generally credit card size and shape card bearing one or two computer readable chips) are known. As shown in FIG. 1, smart card system 100 includes: reciprocating card reader 102 and card assembly 130. Card reader 102 includes: frame 106; card recess 104; reader electronics sub-assembly 110; reader head sub-assembly 112; first side wall 114; rear wall 116; second side wall 118; and communications line 120. Card assembly 130 includes: card main body 132; and chip 134. Card main body 132 includes: first peripheral edge 132a; read edge 132b; and second peripheral edge 132c. 
Card reader 102 is called a “reciprocating” card reader because a card is inserted in an insertion direction, and later removed from the card reader by actuating the card in a direction opposite to the insertion direction.
In order for card reader 102 to read card assembly 130, chip 134 should be in close proximity to head 112. The card main body and card hole of the card reader are sized and shaped so that the card assembly can be reliably seated in the card hole (by moving the card in the direction of arrow E) so that the chip on the card and head on the reader will be in close proximity and alignment when the card is fully seated in the reader. More specifically, edges 132a, 132b, and 132c, respectively engage walls 114, 116, and 118 of the reader. When this engagement exists, the chip will be in close proximity to the head, so that reliable data communication can take place between the chip and the head. In most chip and head designs, the head must actually physically contact the outer major surface of the chip in order for there to be data communication between the chip and the head. Moreover, this physical contact must occur at a fairly precise location with respect to the chip and the head. In addition to the side and rear walls 114, 116, and 118, frame 106 may include top and bottom walls to engage and guide the top and bottom major surfaces of the card. After the reader has read the card, the card is removed by pulling it out of the reader in the counter-E direction (that is, the direction opposite to the E direction).